Zonation of the biota is easily observed on exposed rocky shores. The shore 

 appears as a series of dark red, brown, white, and black, or gray bands 

 (figure 4-27). The red is caused by the red alga, Irish moss, while the brown 

 is the result of dominance by one of several brown algae from the genera 

 Ascophyllum or Fucus . The white band is made up of a pavement of the barnacle 

 B. balanoides . The next higher band, often called the black zone, is caused 

 by a film of blue-green algae on the rocks. 



Fauna of specific zones at 13 sites on Maine's exposed bedrock shores (Doggett 

 et al. 1978; and Larsen and Doggett, in press ) are listed in table 4-11. 



HIGH INTERTIDAL OR BLACK ZONE 



^' ^ "^fc"*^ periwinkles, blue-green algae 



BARNACLE ZONE 



rock barnacles, blue mussels 



ROCKWEEDZONE 



rockweeds 



Figure 4-27. Schematic representation of the intertidal zonation patterns 

 on exposed rocky shores in coastal Maine. 



4-82 



